Although the art, such as international patent publication WO 2007/097944 B2, recognize that thermal management of compression ignition engines during low load conditions can be problematic, there may be so many different and cross coupled control choices available that finding a combination of control choices that produce an acceptable aftertreatment inlet temperature, an acceptable NOx to soot ratio, an acceptable NOx flow rate, an acceptable particulate matter flow rate and finally an acceptable exhaust volumetric flow within known constraints can be extremely elusive.
Exhaust aftertreatment systems for compression ignition engines may include at least one of a diesel particulate filter and a NOx reduction system. Proper operation of these aftertreatment systems typically require that aftertreatment inlet conditions exceed some temperature threshold, such as 300° C. This minimum temperature is often required for particle trap regeneration, urea deposit removal and effective operation to reduce tailpipe out emissions.
The present disclosure is directed toward one or more of the problems set forth above.